Fuzzy analysis of a viscoelastic damper in seismic retrofit of structures

Due to the dependency of viscoelastic materials on the input frequency, amplitude, and temperature, the effectiveness of a viscoelastic damper changes depending on loading and environmental conditions. Generally, this is neglected in the seismic design of structures with viscoelastic dampers due to the complexity in mathematical modeling and nonlinear analysis. This study developed a kriging model for predicting mechanical properties of a viscoelastic damper based on experimental data, and applies it to fragility analysis of a case study structure retrofitted with viscoelastic dampers. Fuzzy analysis was carried out to investigate the effectiveness of the damper in uncertain conditions, including both stochastic and informal uncertainties. The results showed that the proposed analytical scheme can adequately simulate the seismic performance of the viscoelastic damper with uncertain parameters, and that even under the worst combination of the VED mechanical properties, the probability of reaching all limit states was greatly reduced after installation of the VEDs.